/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.beans.factory.support;

import java.lang.reflect.Constructor;
import java.lang.reflect.Method;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.lang.Nullable;

/**
 * Interface responsible for creating instances corresponding to a root bean definition.
 *
 * <p>This is pulled out into a strategy as various approaches are possible,
 * including using CGLIB to create subclasses on the fly to support Method Injection.
 *
 * @author Rod Johnson
 * @author Juergen Hoeller
 * @since 1.1
 */
public interface InstantiationStrategy {

    /**
     * Return an instance of the bean with the given name in this factory.
     *
     * @param bd       the bean definition
     * @param beanName the name of the bean when it's created in this context.
     *                 The name can be {@code null} if we're autowiring a bean which doesn't
     *                 belong to the factory.
     * @param owner    the owning BeanFactory
     * @return a bean instance for this bean definition
     * @throws BeansException if the instantiation attempt failed
     */
    Object instantiate(RootBeanDefinition bd, @Nullable String beanName, BeanFactory owner)
            throws BeansException;

    /**
     * Return an instance of the bean with the given name in this factory,
     * creating it via the given constructor.
     *
     * @param bd       the bean definition
     * @param beanName the name of the bean when it's created in this context.
     *                 The name can be {@code null} if we're autowiring a bean which doesn't
     *                 belong to the factory.
     * @param owner    the owning BeanFactory
     * @param ctor     the constructor to use
     * @param args     the constructor arguments to apply
     * @return a bean instance for this bean definition
     * @throws BeansException if the instantiation attempt failed
     */
    Object instantiate(RootBeanDefinition bd, @Nullable String beanName, BeanFactory owner,
                       Constructor<?> ctor, @Nullable Object... args) throws BeansException;

    /**
     * Return an instance of the bean with the given name in this factory,
     * creating it via the given factory method.
     *
     * @param bd            the bean definition
     * @param beanName      the name of the bean when it's created in this context.
     *                      The name can be {@code null} if we're autowiring a bean which doesn't
     *                      belong to the factory.
     * @param owner         the owning BeanFactory
     * @param factoryBean   the factory bean instance to call the factory method on,
     *                      or {@code null} in case of a static factory method
     * @param factoryMethod the factory method to use
     * @param args          the factory method arguments to apply
     * @return a bean instance for this bean definition
     * @throws BeansException if the instantiation attempt failed
     */
    Object instantiate(RootBeanDefinition bd, @Nullable String beanName, BeanFactory owner,
                       @Nullable Object factoryBean, Method factoryMethod, @Nullable Object... args)
            throws BeansException;

}
